叶片衰老启动和进程受重要内部因子如植物激素的严格调控。生长素在叶片衰老调控中的作用在历经曲折后终于日趋清晰，但具体机制仍不明确。Aux/IAA家族在生长素信号转导路径中处于核心地位，是生长素精确调控多种植物生长发育过程的关键。早期转录组分析显示，多个Aux/IAA基因的表达水平在叶片衰老过程中发生显著变化，但一直未引起重视。我们近期发现，Aux/IAA家族成员AXR2/IAA7是拟南芥叶片衰老的负调节因子，并且该家族的一个或多个成员可能是生长素信号路径与AtSARK和蛋白磷酸酶SSPP所介导的叶片衰老信号转导路径的重要节点。本项目拟申请利用多种技术手段，系统研究Aux/IAA家族成员在叶片衰老过程中的功能和作用机制，深入解析其与AtSARK和SSPP介导的叶片衰老路径的相关性，拓展和完善人们对叶片衰老调控中生长素功能的全面认知，具有重要的科学意义和创新性。

The onset and progression of leaf senescence are tightly regulated by internal factors such as phytohormones. As the first discovered phytohormone, the role of auxin in leaf senescence has become increasingly clear, but the underlying mechanisms remain elusive. Aux/IAA gene family locates at the core of the auxin signal transduction pathway and is the key for auxin to accurately regulate various plant growth and development processes. Early transcriptome analysis showed that multiple Aux/IAA genes are differentially regulated during leaf senescence, but follow-up studies are scarce. We recently found that AXR2/IAA7 is a negative regulator of leaf senescence. In addition, one or more members of the Aux/IAA family may represent an important hub that integrates auxin signaling with AtSARK-SSPP mediated leaf senescence signaling. This project aims to systematically investigate the functions of Aux/IAA gene family in leaf senescence, further explore the molecular mechanisms underlined and comprehensively analyze the correlations between Aux/IAAs and AtSARK-SSPP pathway, leading to improved understanding towards the role of auxin in leaf senescence.